Title: | A semipaparametric view to dimension reduction |
Speaker: | Prof. MA Yanyuan, Department of Statistics, Texas A&M University, USA |
Time/Place: | 10:00 - 11:00 FSC1217, Fong Shu Chuen Library, HSH Campus, Hong Kong Baptist University |
Abstract: | We provide a novel and completely different approach to dimension reduction problems from the existing literature. We cast the dimension reduction problem in a semiparametric estimation framework and derive estimating equations. Viewing this problem from the new angle allows us to derive a rich class of estimators, and obtain the classical dimension reduction techniques as special cases in this class. The semiparametric approach also reveals that in the inverse regression context while keeping the estimation structure intact, the common assumption of linearity and/or constant variance on the covariates can be removed at the cost of performing additional nonparametric regression. The semiparametric estimators without these common assumptions are illustrated through simulation studies and a real data example. |
Title: | Cure Rate Quantile Regression for Censored Data with a Survival Fraction |
Speaker: | Dr. YIN Guosheng, Dept of Statistics & Actuarial Science, The University of Hong Kong, Hong Kong |
Time/Place: | 11:00 - 12:00 FSC1217, Fong Shu Chuen Library, HSH Campus, Hong Kong Baptist University |
Abstract: | Censored quantile regression offers a valuable complement to the traditional Cox proportional hazards model for survival analysis. Survival times tend to be highly right-skewed in the presence of a substantial fraction of long-term survivors who are either cured or immune to the event of interest in the study. We propose cure rate quantile regression for such survival data, which allows for the common censoring scheme that survival times and censoring times are conditionally independent given the covariates. Specifically, we use censored quantile regression to fit the survival times of the susceptible subjects and logistic regression to model the indicators whether patients are susceptible. We study martingale-based estimating equations for parameter estimation and take iterative algorithms to minimize the L1-type convex function. We establish the uniform consistency and weak convergence properties for the estimators of the model parameters. The practical utility of the proposed method is evaluated through both simulated and real data sets. |
Title: | Regularities of Solutions for a Class of Degenerate Equations |
Speaker: | Prof. CHEN Hua, Dean of the School of Mathematics and Statistics, Wuhan University, China |
Time/Place: | 11:00 - 12:00 FSC1217, Fong Shu Chuen Library, HSH Campus, Hong Kong Baptist University |
Abstract: | In this talk, I would report some recent joint results on the Gevrey (or analytic) regularities of solutions for some degenerate partial differential equations, which including (1) generalized Kolmogorov equations (i.e. a linear model of the Boltzmann equation), (2) Fokker-Planck equations, (3) Landau equations and (4) sub-elliptic Monge-Ampere equations. |
Title: | Splines over T-meshes and Applications |
Speaker: | Prof. CHEN Falai, Department of Mathematics, University of Science and Technology of China, China |
Time/Place: | 11:00 - 12:00 FSC1217, Fong Shu Chuen Library, HSH Campus, Hong Kong Baptist University |
Abstract: | In this talk, I will introduce the notion of splines over T-meshes--a new type of local refinement splines. The theoretic problems such as the dimesion of the spline space, the construction of basis functions with good properties are discussed. The applications of the new local refinement splines in Geometric Modeling, Isogeometric. Analysis and solving numerical PDEs are addressed. |
Title: | Colloquium delivered by Dr. Lin-Wang WANG |
Speaker: | Dr. Lin-Wang WANG, Staff Scientist, Lawrence Berkeley National Laboratory, Berkeley, USA |
Time/Place: | 14:30 - 15:30 RRS638, Sir Run Run Shaw Building |
Abstract: | One rapidly developing area in scientific computing is the use of general purpose graphic processing units (GPU). In materials science simulations, the plane wave pseudopotential method is the most widely used density functional theory (DFT) simulation method. We have implemented our plane wave pseudopotential code PEtot using GPU. This requires a redesign of the parallelization algorithm. In particular, we calculate the band to band overlapping matrix elements in G-space parallelization, with the wave function to Hamiltonian application in band index parallelization. We found that it is possible to accelerate the original MPI code by a factor of 20 by the GPU code. As a result, in a molecular dynamics (MD) simulation of a 512 atom GaP system, each MD step takes only about 10 seconds using 256 GPUs. |
We organize conferences and workshops every year. Hope we can see you in future.
Learn MoreProf. M. Cheng, Dr. Y. S. Hon, Dr. K. F. Lam, Prof. L. Ling, Dr. T. Tong and Prof. L. Zhu have been awarded research grants by Hong Kong Research Grant Council (RGC) — congratulations!
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